Process for spinning acrylic fibers

ABSTRACT

fibers of a polymer containing at least 40% by weight of acrylonitrile units, at least 15% by weight of vinyl chloride units and at least 1% by weight of units of an ethylenically unsaturated sulfonate salt compound which have improved dye yield and luster stability are prepared by dry-spinning fibers of the polymer in an organic solvent and wash-drawing the fibers at a draw ratio of at least 2.2X in an aqueous bath maintained at an elevated temperature, thereby reducing the solvent content of the fiber to less than 3.5% by weight of the fiber. The wash-draw step may be carried out in one or more stages and preferably in at least two stages, the first of which involves a draw of 1.15-1.5X at 40°-60° C. Drying is preferably carried out by subjecting relatively wet fibers (80% moisture) to a high temperature (about 150° C).



